1. Field of the Invention
The present invention relates to a printing apparatus having a standby mode and an energy saving mode or a multi-function peripheral.
2. Description of the Related Art
In general, a printing apparatus or a digital multi-function peripheral (MFP) has a standby mode (standby state or ready state) and an energy saving mode (energy saving state) and has a function of changing to the other state under predetermined conditions. The standby state is a state where the printing apparatus or the digital multi-function peripheral is capable of immediately starting up a printing processing upon reception of print data. The energy saving state is a state where the power consumption is saved in comparison with in the standby state. For example, the transition from the ready state to the energy saving state occurs in the event that the ready state has continued for a longer time period than a pre-determined time period. In many cases, the time period before the transition to the energy saving mode is set to be considerably short. Accordingly, when a user intends to output print data, the printing apparatus has been changed to the energy saving mode in many cases. In order to cause the printing apparatus which has been changed to the energy saving mode to start printing processing, it is necessary to change from the energy saving mode to the ready state, which requires a certain time period. For example, an electrophotographic printing apparatus or an MFP requires 30 seconds to change to the ready state from the energy saving mode. During this time period, electricity is supplied to the fixing section in order to raise the temperature at the fixing section to a predetermined temperature, and initial operations required for the mechanism or electrophotographic processing are performed.
Japanese Unexamined Patent Application No. 10-233907 discloses a facsimile apparatus which is usually set to an energy saving mode and stores received fax data in a memory and comprehensively prints and outputs the fax data stored in the memory at time designated by a user or outputs it according to whether or not the remaining memory capacity has reached a specified capacity, thereby saving the consumed power.
If the time interval between successive printing processes is shorter or significantly longer than the waiting time before the transition of the printing apparatus to the energy saving mode, it is possible to attain energy saving while maintaining the usability for users. However, when the time interval between printing processes is compatible with the waiting time before the transition to the energy saving mode, if the printing apparatus is restored from the energy saving mode every time printing processing is performed, this will require a longer time period for restoring it to the ready state. On the other hand, the restoration to the ready state, printing processing, the transition to the energy saving mode and the restoration to the ready state are successively repeated, which prevents an energy saving effect to be attained.
To cope therewith, there has been suggested a method for changing the setting of the waiting time before the transition to the energy saving mode, depending on to the usage. However, the intervals between printing processes are variable and, therefore, it is not necessarily easy to find a proper set value. Further, if the usage is variable depending on the time slot in a day, the day and the season, changing the setting for each time slot, each day and each season is a burdensome operation for the user.
On the other hand, some printing processes require immediate output while other printing processes only require collective pick up of printout at a convenient time, and these printing processes are mixed. However, conventional printing apparatuses have processed print data required to be processed in the order of reception.